Interleukin-6-knockdown of chimeric antigen receptor-modified T cells significantly reduces IL-6 release from monocytes

作者：Liqing Kang, Xiaowen Tang, Jian Zhang, Minghao Li, Nan Xu, Qi Wei, Jingwen Tan, Xiaoyan Lou, Zhou Yu, Juanjuan Sun, Zhenkun Wang, Haiping Dai, Jia Chen, Guoqing Lin, Depei Wu, Lei Yu · 发表于：Experimental Hematology and Oncology · 年份：2020 · DOI：10.1186/s40164-020-00166-2 · 被引用次数：74 · 研究领域：CAR-T cell therapy research、Virus-based gene therapy research、Immune Cell Function and Interaction

BACKGROUND: T cells expressing a chimeric antigen receptor (CAR) engineered to target CD19 can treat leukemia effectively but also increase the risk of complications such as cytokine release syndrome (CRS) and CAR T cell related encephalopathy (CRES) driven by interleukin-6 (IL-6). Here, we investigated whether IL-6 knockdown in CART-19 cells can reduce IL-6 secretion from monocytes, which may reduce the risk of adverse events. METHODS: Supernatants from cocultures of regular CART-19 cells and B lymphoma cells were added to monocytes in vitro, and the IL-6 levels in monocyte supernatants were measured 24 h later. IL-6 expression was knocked down in regular CART-19 cells by adding a short hairpin RNA (shRNA) (termed ssCART-19) expression cassette specific for IL-6 to the conventional CAR vector. Transduction efficiency and cell proliferation were measured by flow cytometry, and cytotoxicity was measured by evaluating the release of lactate dehydrogenase into the medium. Gene expression was assessed by qRT-PCR and RNA sequencing. A xenograft leukemia mouse model was established by injecting NOD/SCID/γc-/- mice with luciferase-expressing B lymphoma cells, and then the animals were treated with regular CART-19 cells or ssCART-19. Tumor growth was assessed by bioluminescence imaging. RESULTS: Both recombinant IL-6 and CART-19 derived IL-6 significantly triggered IL-6 release by monocytes. IL-6 knockdown in ssCART-19 cells dramatically reduced IL-6 release from monocytes in vitro s...